Although there are a total of three Guardian Spirits you can choose to start with in Nioh, there are actually more. During your playthrough you will have access to these additional spirits, providing great opportunity to customize your playstyle.
Below we'll briefly go over where all Guardian Spirits are acquired.
Daiba-Washi (Bird)
Starter spirit.
Fuse-Ushi (Bull)
Available after completing 'Main Mission - Deep in the Shadows (level 12)'.
Isonade (Shark)
Starter spirit.
Kato (Wolf)
Starter spirit.
Mizuchi (Dragon)
Available after completing 'Sub Mission Kanbei and the Overlord (level 18)'.
Raiken (Hound)
Available after compleing 'Main Mission - The Spirit Stone Slumbers (level 19)'.
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Embark on an inspiring mission of human connection beyond the UCA. Sam — with companions by his side — sets out on a new journey to save humanity from extinction. Join them as they traverse a world beset by otherworldly enemies, obstacles and a haunting question: should we have connected?